Deep-sea benthic boundary layer communities and food supply: A long-term monitoring strategy

Long-term monitoring of deep-ocean processes is essential for understanding the potential impacts of climate variation on the deep sea. A suite of autonomous and cabled instrumentation has been developed to allow continuous measurements of food supply availability, species composition and abundance, and organism activity. A sedimentation sensor combines a traditional sediment trap configuration with a digital-imaging system and fluorometer to monitor food supply. A digital time-lapse camera system captures high-resolution images of the sea floor to monitor benthic fauna and sediment processes. A bottom-transiting vehicle conducts photographic transects across the sea floor and measures sediment community oxygen consumption at multiple sites. An upward-looking acoustic array measures backscatter targets, pelagic fauna, passing through an insonified field above the sea floor. Although these instruments can be deployed autonomously, cabled observatories can now provide continuous power and real-time communications for sustained monitoring of deep-sea benthic boundary layer communities. (C) 2009 Elsevier Ltd. All rights reserved.